Walmart is plowing through its global responsibility goals, cutting down on plastic waste, improving energy efficiency in factories, and reshaping the crop diversity of entire U.S. regions. But it's doing a less-than-stellar job when it comes to doing right by its workers. According to a new report (.pdf file) from the University of California, Berkeley, Walmart could significantly raise the wages of its employees without affecting its low prices. Chronically underpaid people around the country could benefit.

When Walmart inevitably moves into cities like New York City, Boston, Los Angeles, and San Francisco (all places where it wants to expand this year), its cheapskate policies could actually lower the local average wages. And since the costs of living a comfortable life march inexorably upward (especially in big cities), this is a problem for all of us.

According to UC Berkeley's report, Walmart employees earn 14.5 percent less than other workers in large retail companies. Depressing stuff, but there is any easy enough fix: If Walmart implemented a $12 per hour minimum wage for all employees, it would cost the company $3.2 billion. That is a lot of money, unless you're Walmart, in which case it's just 1% of your overall annual $305 billion in sales. Even if Walmart passed on the entire burden of the wage increase to customers, it would only average out to a cost increase of 46 cents per shopping trip. That's surely something that most Walmart shoppers can afford.

But they wouldn't even have to. Remember Walmart's exceptional energy-saving plans? Perhaps it could take some of the money it will inevitably save from energy and materials efficiency and pass it on to workers. Or it could--gasp--make slightly less money.

There is reason for Walmart to consider this. If the company raises wages, it might garner more community acceptance in the cities where it is trying to expand. Because who doesn't like the idea of a relatively well-paying employer coming to town? It's an especially big deal when that well-paying employer has 1.4 million members in its work force.

So come on, Walmart: It's time to believe that being good to your workers is as important as making clean energy. We want to stop having to wince when we champion your excellent environmental record.